To read blood pressure, you look at two numbers expressed in millimeters of mercury (mmHg), written as "systolic/diastolic" (e.g., 120/80 mmHg):
- Systolic pressure (top number): This measures the pressure in your arteries when your heart beats and pushes blood out. It is the higher number.
- Diastolic pressure (bottom number): This measures the pressure in your arteries when your heart rests between beats. It is the lower number
For example, a reading of 120/80 mmHg means the systolic pressure is 120 and the diastolic pressure is 80.
How to interpret the numbers:
Blood Pressure Category| Systolic (mmHg)| Diastolic (mmHg)
---|---|---
Normal / Ideal| Less than 120| Less than 80
Elevated / Pre-high| 120–129| Less than 80
High Blood Pressure Stage 1| 130–139| 80–89
High Blood Pressure Stage 2| 140 or higher| 90 or higher
Hypertensive Crisis (emergency)| Higher than 180| Higher than 120
- A reading below 120/80 mmHg is considered healthy and ideal.
- Readings between 120/80 and 140/90 mmHg indicate pre-high blood pressure or elevated risk.
- Readings of 140/90 mmHg or above suggest high blood pressure (hypertension), which may require medical attention and lifestyle changes
How blood pressure is measured:
- A cuff is placed around your upper arm and inflated to temporarily stop blood flow.
- As the cuff deflates, the pressure at which blood flow starts again is the systolic pressure.
- The pressure when blood flow sounds disappear is the diastolic pressure.
- Measurements are often taken using automated devices or manually with a stethoscope
Important notes:
- Blood pressure can vary based on activity, stress, position, and other factors.
- Diagnosis of hypertension usually requires multiple readings on different days.
- Maintaining blood pressure in the normal range reduces risk of heart disease and stroke
In summary, reading blood pressure involves understanding the two numbers, systolic over diastolic, and comparing them to standard categories to assess cardiovascular health.
